Actually, you made this way harder than it is.
You have two similar right triangles.
Set up a proportion using the ratios of the heights and shadows.
On a sunny day, a tower casts a shadow 35.2m long. At the same time, a 1.3m parking meter that is nearby casts a shadow 1.8m long. How high is the tower to the nearest tenth of a metre?
Triangle formed by parking meter:
Triangle formed by tower (Total triangle):
*The value was obtained by adding and .
*The value was obtained by subtracting and from .
Therefore, the height of the tower is .
Textbook answer: .
Where did I make the mistake?